udp_recv.c

   1 /*
   2  * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6 /** \file udp_recv.c Paraslash's udp receiver */
   7
   8 #include <regex.h>
   9 #include <dirent.h>
  10 #include <sys/socket.h>
  11 #include <net/if.h>
  12
  13 #include "para.h"
  14 #include "error.h"
  15 #include "portable_io.h"
  16 #include "list.h"
  17 #include "sched.h"
  18 #include "ggo.h"
  19 #include "recv.h"
  20 #include "udp_recv.cmdline.h"
  21 #include "string.h"
  22 #include "net.h"
  23 #include "fd.h"
  24 #include "buffer_tree.h"
  25
  26 /** The size of the receiver node buffer. */
  27 #define UDP_RECV_CHUNK_SIZE (128 * 1024)
  28 /**
  29  * Data specific to the udp receiver.
  30  *
  31  * \sa \ref receiver, \ref receiver_node.
  32  */
  33 struct private_udp_recv_data {
  34         /** The socket file descriptor. */
  35         int fd;
  36 };
  37
  38 static void udp_recv_pre_select(struct sched *s, struct task *t)
  39 {
  40         struct receiver_node *rn = container_of(t, struct receiver_node, task);
  41         struct private_udp_recv_data *purd = rn->private_data;
  42         int ret;
  43
  44         if (rn->btrn) {
  45                 ret = generic_recv_pre_select(s, t);
  46                 if (ret <= 0)
  47                         return;
  48         }
  49         para_fd_set(purd->fd, &s->rfds, &s->max_fileno);
  50 }
  51
  52 static int enough_space(size_t nbytes, size_t loaded)
  53 {
  54         return nbytes + loaded < UDP_RECV_CHUNK_SIZE;
  55 }
  56
  57 static int add_rn_output(struct receiver_node *rn, char *buf, size_t len)
  58 {
  59         if (!len)
  60                 return 1;
  61         if (!enough_space(len, rn->loaded))
  62                 return -E_UDP_OVERRUN;
  63         memcpy(rn->buf + rn->loaded, buf, len);
  64         rn->loaded += len;
  65         return 1;
  66 }
  67
  68 static void udp_recv_post_select_nobtr(__a_unused struct sched *s, struct task *t)
  69 {
  70         struct receiver_node *rn = container_of(t, struct receiver_node, task);
  71         struct private_udp_recv_data *purd = rn->private_data;
  72         int ret;
  73         char tmpbuf[UDP_RECV_CHUNK_SIZE];
  74         size_t packet_size;
  75
  76         if (rn->output_error && *rn->output_error < 0) {
  77                 t->error = *rn->output_error;
  78                 return;
  79         }
  80         if (!FD_ISSET(purd->fd, &s->rfds))
  81                 return;
  82         ret = recv_bin_buffer(purd->fd, tmpbuf, UDP_RECV_CHUNK_SIZE);
  83         if (ret < 0) {
  84                 if (is_errno(ret, EINTR) || is_errno(ret, EAGAIN))
  85                         goto success;
  86                 t->error = ret;
  87                 return;
  88         }
  89         t->error = -E_RECV_EOF;
  90         if (!ret)
  91                 return;
  92         packet_size = ret;
  93         if (packet_size >= FEC_EOF_PACKET_LEN)
  94                 if (!memcmp(tmpbuf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
  95                         return;
  96         t->error = add_rn_output(rn, tmpbuf, packet_size);
  97         if (t->error < 0)
  98                 return;
  99 success:
 100         t->error = 1;
 101 }
 102
 103 #define UDP_RECV_READ_BUF_SIZE 1500
 104
 105 static void udp_recv_post_select_btr(__a_unused struct sched *s, struct task *t)
 106 {
 107         struct receiver_node *rn = container_of(t, struct receiver_node, task);
 108         struct private_udp_recv_data *purd = rn->private_data;
 109         struct btr_node *btrn = rn->btrn;
 110         int ret;
 111         char *buf = NULL;
 112         size_t packet_size;
 113
 114         t->error = 0;
 115         ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
 116         if (ret < 0)
 117                 goto err;
 118         if (ret == 0)
 119                 return;
 120         if (!FD_ISSET(purd->fd, &s->rfds))
 121                 return;
 122         buf = para_malloc(UDP_RECV_READ_BUF_SIZE);
 123         ret = recv_bin_buffer(purd->fd, buf, UDP_RECV_READ_BUF_SIZE);
 124         if (ret == 0)
 125                 ret = -E_RECV_EOF;
 126         if (ret < 0)
 127                 goto err;
 128         packet_size = ret;
 129         if (packet_size >= FEC_EOF_PACKET_LEN) {
 130                 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN)) {
 131                         ret = -E_RECV_EOF;
 132                         goto err;
 133                 }
 134         }
 135         btr_add_output(buf, ret, btrn);
 136         return;
 137 err:
 138         free(buf);
 139         btr_remove_node(btrn);
 140         t->error = ret;
 141 }
 142
 143 static void udp_recv_post_select(__a_unused struct sched *s, struct task *t)
 144 {
 145         struct receiver_node *rn = container_of(t, struct receiver_node, task);
 146         if (rn->btrn)
 147                 return udp_recv_post_select_btr(s, t);
 148         udp_recv_post_select_nobtr(s, t);
 149 }
 150
 151 static void udp_shutdown(void)
 152 {
 153         return;
 154 }
 155
 156 static void udp_recv_close(struct receiver_node *rn)
 157 {
 158         struct private_udp_recv_data *purd = rn->private_data;
 159
 160         if (purd->fd >= 0)
 161                 close(purd->fd);
 162         free(rn->private_data);
 163         free(rn->buf);
 164         udp_recv_cmdline_parser_free(rn->conf);
 165 }
 166
 167 static void *udp_recv_parse_config(int argc, char **argv)
 168 {
 169         int ret;
 170         struct udp_recv_args_info *tmp =
 171                 para_calloc(sizeof(struct udp_recv_args_info));
 172
 173         ret = udp_recv_cmdline_parser(argc, argv, tmp)? -E_UDP_SYNTAX : 1;
 174         if (ret >= 0)
 175                 return tmp;
 176         free(tmp);
 177         return NULL;
 178 }
 179
 180 /*
 181  * Perform AF-independent joining of multicast receive addresses.
 182  *
 183  * \param fd    Bound socket descriptor.
 184  * \param iface The receiving multicast interface, or NULL for the default.
 185  *
 186  * \return Zero if okay, negative on error.
 187  */
 188 static int mcast_receiver_setup(int fd, const char *iface)
 189 {
 190         struct sockaddr_storage ss;
 191         socklen_t sslen = sizeof(ss);
 192         int id = iface == NULL ? 0 : if_nametoindex(iface);
 193
 194         if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0)
 195                 goto err;
 196
 197         if (iface != NULL && id == 0)
 198                 PARA_WARNING_LOG("could not resolve interface %s, using default", iface);
 199
 200         switch (ss.ss_family) {
 201         case AF_INET:
 202                 if (IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr))) {
 203 #ifdef HAVE_IP_MREQN
 204                         struct ip_mreqn m4;
 205
 206                         m4.imr_address.s_addr   = INADDR_ANY;
 207                         m4.imr_ifindex          = id;
 208 #else
 209                         struct ip_mreq m4;
 210
 211                         m4.imr_interface.s_addr = INADDR_ANY;
 212                         if (id != 0)
 213                                 PARA_ERROR_LOG("Setting IPv4 receiver mcast interface not supported.");
 214
 215 #endif
 216                         m4.imr_multiaddr        = ((struct sockaddr_in *)&ss)->sin_addr;
 217
 218                         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &m4, sizeof(m4)) < 0)
 219                                 break;
 220                 }
 221                 return 0;
 222         case AF_INET6:
 223                 if (IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
 224                         struct ipv6_mreq m6;
 225
 226                         memset(&m6, 0, sizeof(m6));
 227                         memcpy(&m6.ipv6mr_multiaddr, &((struct sockaddr_in6 *)&ss)->sin6_addr, 16);
 228                         m6.ipv6mr_interface = id;
 229                         if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &m6, sizeof(m6)) < 0)
 230                                 break;
 231                 }
 232                 return 0;
 233         default:
 234                 PARA_ERROR_LOG("address family %d not supported", ss.ss_family);
 235                 return -E_ADDRESS_LOOKUP;
 236         }
 237 err:
 238         return -ERRNO_TO_PARA_ERROR(errno);
 239 }
 240
 241 static int udp_recv_open(struct receiver_node *rn)
 242 {
 243         struct private_udp_recv_data *purd;
 244         struct udp_recv_args_info *c = rn->conf;
 245         char  *iface = c->iface_given ? c->iface_arg : NULL;
 246         int ret;
 247
 248         rn->buf = para_calloc(UDP_RECV_CHUNK_SIZE);
 249         rn->private_data = para_calloc(sizeof(struct private_udp_recv_data));
 250         purd = rn->private_data;
 251
 252         ret = makesock(AF_UNSPEC, IPPROTO_UDP, 1, c->host_arg, c->port_arg);
 253         if (ret < 0)
 254                 goto err;
 255         purd->fd = ret;
 256
 257         ret = mcast_receiver_setup(purd->fd, iface);
 258         if (ret < 0) {
 259                 close(purd->fd);
 260                 return ret;
 261         }
 262
 263         ret = mark_fd_nonblocking(purd->fd);
 264         if (ret < 0)
 265                 goto err;
 266         PARA_NOTICE_LOG("receiving from %s:%d, fd=%d\n", c->host_arg,
 267                 c->port_arg, purd->fd);
 268         return purd->fd;
 269 err:
 270         free(rn->private_data);
 271         free(rn->buf);
 272         return ret;
 273 }
 274
 275 static void udp_recv_free_config(void *conf)
 276 {
 277         udp_recv_cmdline_parser_free(conf);
 278 }
 279
 280 /**
 281  * The init function of the udp receiver.
 282  *
 283  * \param r Pointer to the receiver struct to initialize.
 284  *
 285  * Initialize all function pointers of \a r.
 286  */
 287 void udp_recv_init(struct receiver *r)
 288 {
 289         struct udp_recv_args_info dummy;
 290
 291         udp_recv_cmdline_parser_init(&dummy);
 292         r->shutdown = udp_shutdown;
 293         r->open = udp_recv_open;
 294         r->close = udp_recv_close;
 295         r->pre_select = udp_recv_pre_select;
 296         r->post_select = udp_recv_post_select;
 297         r->parse_config = udp_recv_parse_config;
 298         r->free_config = udp_recv_free_config;
 299         r->help = (struct ggo_help) {
 300                 .short_help = udp_recv_args_info_help,
 301                 .detailed_help = udp_recv_args_info_detailed_help
 302         };
 303         udp_recv_cmdline_parser_free(&dummy);
 304 }